1. Field of the Invention
The present invention relates to a chamber structure which is arranged in a fuel tank of a vehicle and can keep suction of fuel in response to change in fuel level.
2. Description of the Related Art
As the chamber structure of the vehicle of this type in the related art, the chamber structure set forth in Utility Model Application Publication (KOKAI) Hei 6-83441, for example, etc. have been known.
A chamber is secured to a bottom portion of a fuel tank main body which stores fuel of the vehicle.
A suction opening of a feed pump as the fuel pump is inserted into a chamber body. A through hole for sending out fuel into the a chamber main body is formed in a peripheral wall portion of the chamber main body.
An ejector portion as a negative pressure area is provided in front of the through hole.
An inlet port of a return pipe for supplying the return fuel to the chamber an body is arranged in the ejector portion.
In addition, a recirculation pipe having an upper opening which is arranged below an upper edge of the chamber main body and is directed to the chamber main body and a lower opening which is directed to the ejector portion is provided upward from the ejector portion.
In the chamber structure in the related art, because of an exhaust pressure of the return fuel which is returned by the return pipe, a negative pressure is generated in a clearance portion between the inlet portion and the through hole.
Therefore, residual fuel in the fuel tank which enters from the fuel tank main body to the ejector portion is involved into the return fuel, and then such residual fuel as well as the return fuel is sent out into the chamber main body.
Accordingly, fuel in the chamber mean body can be sucked out stably by the feed pump.
Also, fuel can be flown down from an upper opening of a recirculation pipe into the ejector portion via the recirculation pipe before fuel is flown out from the chamber main body to the fuel tank main body because of an increase in the fuel level in the chamber main body, so that fuel having a relatively high temperature in the chamber main body can be recirculated.
As a result, a higher temperature of fuel in the fuel tank main body in the outside of the chamber can be prevented to thus suppress generation of vapors, and also the temperature of fuel which is sucked and sent out from the fuel pump suction port can be brought close to the temperature of the return fuel.
In addition, since the ejector portion is filled with the tank residual fuel and fuel in the chamber main body, which is flown down via the recirculation pipe, involvement of the air can be prevented.